Custom compiling Espruino for Pico: FAIL - size of 238620 is over 215040 bytes

Ahh - the thing you might have been missing is RELEASE=1 on the command-line. I'll update the docs (they mention it for Linux, but not when building using a VM). Building without RELEASE=1 compiles in debug checks, which take space and slow Espruino down, but which also make sure nothing is going horribly wrong with any changes that might have been made :)

If you take a look in Makefile under ifdef PICO_1V3 you'll see lines titled USE_xxx that you can remove - however the Pico itself has almost certainly got enough free space without doing that - it's only the original Espruino board that's getting a bit tight now.